1. Field of the Invention
The present invention relates to an imaging module and an electronic device, and particularly, to an imaging module having an optical image stabilizer (OIS) function which is mounted on an electronic device such as a smart phone, a portable phone, or a tablet terminal, and an electronic device having the imaging module.
2. Description of the Related Art
FIG. 15 is a schematic view showing an internal configuration of an imaging module 1 having an optical image stabilizer (OIS) function in the related art.
The imaging module 1 mainly comprises a tubular lens barrel 12 which supports a lens group 10, an image stabilizing movable portion 20 which accommodates the lens barrel 12 and has a magnetic member such as a magnet 54, an imaging element 30, an elastic support portion 40 which supports the image stabilizing movable portion 20 so as to be movable in a direction perpendicular to an optical axis of the lens group 10 and to be inclinable around an axis perpendicular to the optical axis, an OIS mechanism 50 which moves the image stabilizing movable portion 20 in a direction orthogonal to the optical axis (in a XY plane), and an focus adjustment mechanism 60 which moves the lens barrel 12 in a direction (Z direction) of the optical axis.
The elastic support portion 40 is configured of a plate spring 42 which extends to the side of the image stabilizing movable portion 20, and four suspension wires 44 of which one end is fixed to the plate spring 42 and the other end is fixed to the imaging element 30 side.
The OIS mechanism 50 is configured of a voice coil motor which is consisted of an OIS drive coil 52 which is fixed to a substrate 32 side (fixed side) on which the imaging element 30 is disposed, and an OIS drive magnet 54 which is fixed to the image stabilizing movable portion 20 side (movable side) and is a magnetic member. In addition, in FIG. 15, a pair of OIS drive coils 52 and a pair of OIS drive magnets 54 are shown in an X direction (a right-left direction in FIG. 15). However, a pair of OIS drive coils 52 and a pair of OIS drive magnets 54 are also provided in the Y direction (a direction orthogonal to a paper surface of FIG. 15). By driving the OIS drive coils in the X direction and the Y direction and moving the image stabilizing movable portion 20 in the direction orthogonal to the optical axis (in the XY plane), it is possible to perform image stabilization.
The focus adjustment mechanism 60 is configured of a voice coil motor which is consisted of an auto focus (AF) coil 62 which is disposed inside the image stabilizing movable portion 20 and an AF magnet 64 which is disposed around the lens barrel 12. By driving the voice coil motor and moving the lens barrel 12 in the direction (Z direction) of the optical axis, it is possible to perform focus adjustment.
The image stabilizing movable portion 20 is disposed (such that the optical axis of the lens group 10 is orthogonal to a light receiving surface of the imaging element 30) so as to directly face the imaging element 30 if possible. However, the imaging module 1 comprising the elastic support portion 40 and the OIS mechanism 50 is influenced by a magnetic field generated from an electronic device on which the imaging module 1 is mounted.
FIG. 16 is a main sectional view of a smart phone 2 in a case where the imaging module 1 is mounted on the smart phone 2. As shown in FIG. 16, a speaker 3 is disposed in the vicinity of the imaging module 1, the imaging module 1 is influenced by a magnetic field (magnetic force) generated by the speaker 3, and as shown in FIG. 17, the image stabilizing movable portion 20 is inclined, and there is a problem that the image stabilizing movable portion 20 does not directly face the imaging element 30.
JP2013-122575A discloses that an image stabilizer is covered by a shield cover, and particularly, in the invention disclosed in JP2013-122575A, a camera cover is not configured of a non-magnetic body but is configured of a magnetic body. In this way, unlike a case where the camera cover is configured of a non-magnetic body, since the camera cover is configured of a magnetic body, a first resonance frequency of a vibration system in an OIS direction is low, a servo gain of a low band increases, and it is possible to increase effects for preventing camera shake.
In addition, JP2009-71495A discloses that in a case where a magnetic force of a speaker which is a magnetic field generation portion is 100 Gauss, a reliable operation of a camera module is ensured if the camera module is separated from a speaker by 10 mm or more.